1. Field of the Invention
The present invention relates to a measuring system, in particular to an image-based refractive index measuring system.
2. Description of the Related Art
Currently, the applications of the refractive index are relatively extensive, for example, a sugar meter that measures the juice sweetness or measures the water salinity that both may use the principle of refraction. The conventional sugar refractive index meter or the refractometer in circulation such as the refractometers disclosed by Republic of China Patent D111526 or D127363. The refractometer is basically a round pipe body that a duckbill shaped portion of the front end is a measure end, which having a head shaped lift cover and having a rectangular lens therein, the round pipe body may drop the liquid into the lens, and the intermediate round pipe body is a gripping portion, the terminal end is a drum-shaped eyecup end, which may view the scale on the lens to know the predicting refractive index or the concentration. In the conventional technology, the user has to visually interpret the scale on the lens by the eye, so as to know the predicting refractive index and the concentration of the predicting analyte. In the long-term use of the environment, it is easy to cause the occupational injury for the user's eyes.
In addition, the sugar detection meter in the Republic of China Patent M398117 and the juice sweetness detection device in the Republic of China Patent M395161, are arranged for measuring the refractive index by the optical manner. However, the sugar detection meter uses the grating spectrometer parts and the infrared detection element architecture, which lead to the complexity of the system design and costly. Therefore, it is more complex in manipulation and the higher cost is the biggest deficiency while using such type of meter.